Board Thread:General Discussion/@comment-33593633-20171117230830/@comment-27248965-20171118002528

First off, UMV Batteries won’t help because you cannot mine for Deep Sea Scales, you find Heart Scales instead.

Are you leading with a Pokémon that has Ability ? This Ability boosts the chance of finding Wild Pokémon with held items. Switch into another Pokémon with Ability.

Chinchou in Cragonos Mines is an alternative. It has 17% encounter rate with Good Rod, but its chance to hold Deep Sea Scale is 5%, which is the same as Blue Basculin, so good luck.